1. Field of the Invention
The present invention relates to an ink jet color recording method utilizing a monochrome ink jet recording technique and to an epoch-making invention, which allows to use a monochrome ink jet recording apparatus as a color recording apparatus. The present invention can be applied to an apparatus for recording an ink of a coloring liquid (to be simply referred to as an ink hereinafter) onto a recording medium such as a paper sheet, a cloth, a transparency (OHP) film, and the like.
2. Related Prior Art
As a color image formation method, a method of performing recording by attaching a liquid ink onto a recording medium has been known before an electrophotographic color recording method, but is applied to a small number of products. On the market, therefore, electrophotographic color recording apparatuses are popular. In general, a recording apparatus, which receives a recording medium, and discharges a recording medium on which a color image in a plurality of colors is formed, is known as a color recording apparatus.
As an ink jet recording apparatus, in past years, a monochrome ink jet recording apparatus capable of performing monochrome recording, and a color ink jet recording apparatus for performing color recording are available. The former apparatus is inexpensive, while the latter apparatus is expensive and large in size. In particular, although the color ink jet recording apparatus can satisfactorily perform recording on a specific recording medium (special-purpose coating paper), it often causes relative deterioration of image quality on various recording media such as normal high-quality paper, or a transparency (OHP) film.
On the other hand, a user who uses the monochrome ink jet recording apparatus sometimes wants to perform color recording although the frequency of such occasions is low. As a result, demand has arisen for a compact, inexpensive color ink jet recording apparatus, which can be easily used by a user.
In a conventional color ink jet recording apparatus, when recording dots are modulated so as to achieve recording with high image quality, the arrangement of the apparatus becomes complicated and bulky, resulting in an expensive apparatus in order to obtain a practical recording speed. For this reason, most of commercially available color ink jet recording apparatuses perform pseudo gradation processing for achieving gradation expression using a plurality of pixels. Thus, deterioration of image quality is observed relative to an electrophotographic color recording apparatus, and the like, which can achieve multi-gradation expression using only one pixel.